Oxyalkylated quinolines

ABSTRACT

A process for the recovery of hydrocarbon materials from a subterranean hydrocarbon-bearing formation by contacting the formation with an aqueous alkaline flooding medium containing a solubilizing agent.

United States Patent Palmer et al.

UXYALKYLATED QUINOLINES Inventors: Harold A. Palmer; Thomas E.

Sample, Jr., both of Houston, Tex.

Assignee: Texaco Inc, New York, NY.

Filed: Mar. 15, 1974 Appl. No.: 451,641

Related US. Application Data Division of Ser. No. 303,170, Nov. 2, 1972, which is a division of Ser. No. 160,142, July 6, 1971, Pat. No. 3,731,741.

US. Cl 260/289 R Int. Cl C071! 33/38 Field of Search 260/289 R References Cited UNITED STATES PATENTS 9/1948 Carlson 260/289 R Primary ExaminerDonald G. Daub Assistant ExaminerDavid B. Springer Attorney, Agent, or FirmT. H. Whaley; C. G. Ries; Walter D. Hunter [57] ABSTRACT A process for the recovery of hydrocarbon materials from a subterranean hydrocarbon-bearing formation by contacting the formation with an aqueous alkaline flooding medium containing a solubilizing agent.

2 Claims, No Drawings 11 @XYAILKYLATED Q UHNCDILIINIES This is a division of application Ser. No. 303,170, filed Nov. 2, 1972, which is a division of application Ser. No. 160,142, filed July 6, 1971, now U.S. Pat. No. 3,731,741

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an improved process for the recovery of hydrocarbon materials from hydrocarbonbearing formations. More particularly, the invention relates to a process in which hydrocarbons, including asphaltic crudes, are recovered from a reservoir by contacting the formation with an aqueous alkaline flooding medium containing a solubilizing agent.

2. Description of the Prior Art The production of petroleum products is usually accomplished by drilling into a hydrocarbon-bearing formation and utilizing one of the well-known recovery methods for the recovery of the hydrocarbons. However, it is recognized that these primary recovery techniques may recover only a minor portion of the petroleum products present in the formation particularly when applied to reservoirs of viscous crudes. Even the use of improved recovery practices involving heating, miscible flooding, water flooding and steam processing may still leave up to 7080% of the original hydrocarbons in place.

Thus, many large reserves of petroleum fluids from which only small recoveries have been realized by present commercial recovery methods, are yet to reach a potential recovery approaching their estimated oil-inplace.

Water flooding is one of the more widely practiced secondary recovery methods. A successful water flood may result in recovery of 50% of the original hydrocarbons left in place. However, generally the application of water flooding to many crudes results in much lower recoveries.

The newer development in recovery methods for heavy crudes is the use of steam injection which has been applied in several modifications, including the push-pull technique and through-put methods, and has resulted in significant recoveries in some areas. Crude recovery by this process is enhanced through the beneficial effects of the drastic viscosity reduction that accompanies an increase in temperature. This reduction in viscosity facilitates the production of hydrocarbons since it improves their mobility, i.e., it increases their ability to flow.

However, the application of these secondary recov ery techniques to depleted formations may leave major quantities of oil-inplace, since the crude is tightly bound to the sand particles of the formation, that is, the sorptive capacity of the sand for the crude is great. In addition, interfacial tension between the immiscible phases result in entrapping crude in the pores, thereby reducing recovery. Another disadvantage is the tendency of the aqueous drive fluid to finger, since its viscosity is considerably less than that of the crude, thereby reducing the efficiency of the processes.

Consequently, process modifications have been de veloped which may incorporate additives to lessen the above cited disadvantages and thereby improve the efficiency of these processes. For example, surface-active agents and miscible liquids are utilized to decrease the interfacial tension between the water and the reservoir crude, and thickeners have been developed to adjust viscosity so as to inhibit fingering.

The practiced methods for the injection of additives commonly consist of injection of a slug of additive, contained in a transporting medium, e.g., water, into the formation and then following this injection with a flood water to move the additive slug through the formation. In its ideal effect, the so-called slug moves through the formation as an additive bank, thereby im parting its beneflciating effects to the recovery process.

In many hydrocarbon-bearing formations it is common to find the oil sands to be preferentially wetted by oil. It is we'll known in the art to inject into these preferentially oil-wetted formations certain chemicals to reverse the wettability characteristics of the formation, thereby increasing the effectiveness of a water flood to remove the residual crude. For example, a dilute alkaline aqueous solution is known to increase the wetting characteristics of sand surfaces, and promote a leaching action and emulsification of the tarry materials. Those solutions have been used as slugs in conjunction with subsequent steam injection processes to force the emulsion thus formed through the formation to a production well.

Improved recoveries from heavy crudes or tar sands have been realized also by the use of dilute aqueous alkaline solutions containing an effective amount of nonionic surfactant, whereby extraction is effected by the spontaneous emulsiflcation when the aqueous liquid comes in contact with the tar in the sand.

However, some of the disadvantages of those additive recovery processes include the problem that the additive may be strongly absorbed in the surfaces of the sand formation, resulting in a large or excessive amount of additive being required. The costs involved of these additives, which may be relatively expensive, may become excessive early in the life of the recovery process necessitating its termination. Other disadvantages include the unfavorable viscosity ratio between the flooding medium and the crude.

It is known that the recovery of oil by injection of water or other fluids varies substantially from one formation to another and it is believed that the asphalt content of the hydrocarbons of some formations is at least a major factor responsible for this variation. A variety of known asphalt dispersants have been employed in flooding media on the theory that such materials would substantially improve hydrocarbon recovery in those instances where asphalt was present in the native hydrocarbon, however, the use of such materials has not been particularly effective, probably because of the limited solubility of such agents in the normally employed flooding fluids. There is a definite need in the art, therefore, for a recovery process employing asphalt dispersants with improved solubility characteristics.

One of the principal objects of this invention is to provide an improved process for increasing the ultimate recovery of hydrocarbon from a hydrocarbonbearing formation.

Another object of this invention is to provide an efficient method for the recovery of hydrocarbon from a hydrocarbon-bearing formation in which an aqueous alkaline flooding medium containing as a solubilizing agent a water-soluble, oxyalkylated, nitrogen containing aromatic compound is utilized.

BRIEF SUMMARY OF THE INVENTION This invention relates to a method for recovering' h ydrocarbons from a subterranean hydrocarbon-bearing formation having in communication therewith at least one injection well and one production well comprising:

a. injecting into the said formation through said injection well an aqueous alkaline flooding medium containing a solubilizing agent comprising a water-soluble, oxyalkylated, nitrogen-containing aromatic compound, such as a solution of ethoxylated 8-hydroxy-quinoline, propoxylated nitrophenol, etc., made alkaline with sodium hydroxide,

b. forcing said alkaline flooding medium through the formation, and

c. recovering hydrocarbons through said production well.

DETAILED DESCRIPTION OF THE INVENTION The aqueous alkaline flooding medium employed in the process of this invention comprises an aqueous medium which can be, for example, steam, hot water, a mixture of hot water and steam or cold water together with an alkaline agent. Useful alkaline agents include compounds selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide, and a basic salt of the alkali metal, or alkaline earth metal which is capable of hydrolyzing in an aqueous medium to give an alkaline solution, the concentration of the alkaline agent being about 0.001 to about 0.5 molar to give the required alkaline solution. Examples of the especially useful alkaline agents include sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonium hydroxide, sodium carbonate and potassium carbonate, etc.

Solubilizing materials useful in the process of this invention include water-soluble, oxyalkylated nitrogencontaining aromatic compounds where preferably the aromatic compound contains not more than 12 carbon atoms and the number of oxyalkyl units is about to about 50.

An especially useful group of the watersoluble, oxyalkylated, nitrogen-containing aromatic compounds include compounds of the formulae:

wherein R is selected from the group consisting of:

wherein R is alkylene of from 2 to 4 inclusive carbon atoms, and m is an integer of from about 5 to about 50 and, preferably, from about 5 to about 20.

The novel water-soluble oxyalkylated products 0 thisinvention can be conveniently prepared by a number of processes well-known in the art. For example, the alkylene oxide can be reacted with the initiator dissolved in a suitable solvent throughout which an alkaline catalyst, such as'potassium hydroxide or sodium hydroxide, is uniformly dispersed. The quantity of the catalyst utilized generally will befrom'about 0.15 to about 0.1 percent by weight of the reactants. Prefera-' bly, the reaction temperature will range from about from about 1 to about 20 hours or more depending on the particular reaction conditions employed. This process is more completely described in US. Pat. No. 2,425,845.

The solubilizing agent should be present in the aqueous solution in sufficient concentration to effect the emulsification of the hydrocarbon material and maintain them in this state during passage through theformation. Concentrations in solutions of from about 0.05 to about 5.0 percent by weight of the solubilizing agent are usually sufficient, although smaller or larger amounts may be employed satisfactorily in some cases.

The advantageous results achieved with the aqueous alkaline flooding medium used in the process of this invention are believed to be derived from the wettability improving characteristics of the alkaline agent and the solubilizing action of the solubilizing agent on the crude oil such as in tar sands and in other formation and especially on the asphaltene fractions. The solubilizing agent is believed to be effective in releasing the crude from the pore surfaces or the sand surfaces as the case may be so that the surfaces can be exposed to the alkaline agent.

A further advantage of the aqueous alkaline flooding medium of this invention is believed to result from its ability to emulsify the extracted crude to form an oil in water emulsion. The effectiveness of the flooding medium is also thought to result to a great extent from its action on the heavier complex hydrocarbon materials referred to as asphaltenes present to some extent in all crudes and especially in low-gravity viscous crudes and oils such as those found in tar sands which are extremely difficult to recover. It has been shown that asphaltene fractions are responsible in a large part for the adhesive force which many oils and especially heavy crudes and tars have for the mineral surfaces of the hydrocarbon-bearing formations.

In operating the process of this invention one embodiment may consist of drilling an injection well into the formation through which the aqueous alkaline flooding medium is injected into the formation. The flooding medium may be injected continuously or a slug of the aqueous alkaline flooding medium containing the solubilizing agent may be injected into the formation followed by injection of a slug of an aqueous drive fluid such as water, hot water, or steam.

During the passage of the aqueous alkaline flooding medium of this invention which contains the solubilizing agent hydrocarbons are stripped from the formation, forming an oil in water emulsion which can then be produced at neighboring wells. Recovery of the hydrocarbons from the emulsion can be accomplished by any one of several well known emulsion breaking tech- 7 niques.

Preparation of Ethoxylated-8-I-Iydroxy Quinolines A series of four polyethoxylated-8-hydr0xy quinoline solubilizing agents having the general formula:

' where n is the number of oxyethyl units were prepared as described below:

To a 250 ml reaction flask there was added 27.2 grams (0.068 mole) of polyethylene glycol (mol. wt. 4-00) and 3.7 grams (0.066 mole) of potassium hydroxide. The reaction mixture was heated gently until the an aqueous alkaline flooding medium and as a solubilizing agent Products A, B, C or D were carried out. Small sand packs were prepared using 150/200 mesh Ottawa sand and having pore volumes of approximately 30 ml.

potassium hydroxide had dissolved at which time the 5 The packs were Saturated with brine which was telglpemwle 3 contents of the flask was about placed with Slocum crude oil(AlPl gravity 17.5)toirre- 80 C. A total or 9.7 grams (0.0625 mole) of 8- W 1 A ducible water saturation. in the next step the oil saturanyoroxyquinoiine was added LO the reaction flask over p I .0 1 tion of tne packs was reduced to approximately 80 pera period O1 10 minutes aiter which the reaction mixture was heaied to O and held m that tempera 10 cent by flooding with 8 pore volumes of distilled water. ture for 4- hours. After standing overnight, the reaction Thls mmal Waterflood was followfid by the mlectlon mixture was steam distilled to remove unreacted polyeach 01' 8 pore Volumes Ofoj Volume percent ethylene glycol and water was then removed from the Of 3 5011100 of Products respecnvely at three oxyallcylated product by evaporation. Yield: 33 grams. ffieni P Values namely 12 and The amount of The molecular weight of the product was determined 15 oil recovered was measured and the results obtained in dimethyl formarnide solution using a vapor pressure are shown in Table 2. osinometer and found t0 be 4 8 (Pr d l- Results obtained in two additional comparative tests, :dddlllonal Polyellloxylamd fl l' P one with quinoline as a solubilizing agent (CT-1) and P Pmducls C 'f D) utilizing a second with alkaline water alone (CT-2) are also set hydroxyquinoline as the initiator in the same manner as forth in Table 2 described above except that polyethylene glycols having respectively molecular weights of 300, 600 and Tab? 2 1.000 were employed. Details relating to these four polyethoxylated compounds are set forth in Table 1 EFFECT OF SOLUBILIZING AGENTS ON OIL RECOVERY u 1 I 7 Percent Recovery of Oil wl lc'l lollows Solubilizing M01. Remaining after Waterfloods" Tablg 1 Ex. Agent Wt. at pH 7 at pH 12 at pH 13 y y 1 A 365 21.7 28.0 41.5 Molecular Weights or Polyethoxylzvr/ted lil-H droxyquinolines I] B 478 170 28.3 582 Product Molecular cig t n I" C 630 10.4 46,7 69.4 365 5 iv D 886 17.2 45.3 72.2 f;- 478 8 cm Quinoline 129 18.1 49.6 34.0 C 630 H (T-2 None 15.3 44.8 17.4 D 886 17 pH adjusted \\ilh sodium hydroxide.

a r E h l d 8 Q S In A The data presented in Table 2 indicates that oil rer "1 1 i Home c1 re'ummon 01 L Oxy ale u no L A covery increases as the molecular weight of the polye- Equal quantities by Weight of g'qumolmesulfomc thoxylated solubilizing agent increases and as the p111 of acid i PhQSPhOTOUS lwmfachlorlde were ground the flooding medium increases. Further. it is shown in game? a mortar; T1115 mixture was l refluxed at 40 Table 2 that substantially higher oil recoveries can be algploxlmatly C for 3 g 9 l f f zl achieved utilizing the aqueous alkali flooding media of t reaction mixture gave qumo mesu (my C 0 this invention over that obtained when quinoline is emri e.

10 ed in the a ueous alkaline medium or when water Seven grams (0.031 moles) of the 8- 5 0:6 s utiliz quinolinesulfonyl chloride was gradually added to a I H d l b mixture of polyethylene glycol (mol. wt. 600, 0.034 a manner mcrease 01 recovery 6 moles) and 1.7 grams of potassium hydroxide which aChIQYed h for example, ethoxylated 8-qu1nolme had been preheated to The mix/[um was then sullonic acid of molecular weight 764 or the other heated to a temperature of 140150C. and allowed to above-described oxyalkylated Products are p y remain at that temperature for 4 hours. After work-up in the process of this invention. the product. ethoxylated 8-quinolinesulfonic acid, was What is claimed is: obtained in about 75 percent yield. The molecular l.Awater-soluble,oxyalkylated.nitrogen-containing weight of the product was determined at 62C. in (11- aromatic Compound f h f l methyl formamide solution utilizing a vapor pressure R(OR)M osmometer and found to be 764 (theoretical 79 1). wherein R is Three additional ethoxylated quinoline sulfonic acid derivatives were prepared in the same manner as described above by reacting equimolar quantities of a polyethylene glycol having a molecular weight or" 200,

and 1.000 respectively with 8-quinolinesulfonyl 6O chloride. each instance the yield of the desired product was about 75 percent. I I: 7

The following examples which illustrate various emwherein R a l of to 4 mcluslve Carbon bodiments of this invention are to be considered not alom$- and m 15 an Integer OT 5 t0 lim ative 2. The compound of claim 11 wherein R is:

EXAMPLE Lil/ A series or now 

1. A WATER-SOLUBLE, OXYALKYLATED, NITROGEN-CONTAINING AROMATIC COMPOUND OF THE FORMULA: R(OR'')MOH, WHEREIN R IS QUINOLINYL, WHEREIN R'' IS ALKYLENE OF FROM 2 TO 4 INCLUSIVE CARBON ATOMS, AND M IS AN INTEGER OF 5 TO
 50. 2. The compound of claim 1 wherein R'' is: -CH2-CH2- . 